Room-Temperature Defect Tolerance of Shape Engineered Quantum Dot Structures

摘要

A quantum dot (QD) medium is expected to demonstrate superior performance in various devices when compared with quantum wells (QWs). One area of interest has been the improved defect tolerance of QD media, though it was demonstrated at low temperatures so far. In this study, the defect tolerance of shape-engineered QD structures is compared with that of a QW structure at temperatures up to 300 K. To create high defect densities both QD and QW structures were irradiated with high energy (1.5 MeV) protons (with doses up to 3 x 10~(14) cm~(-2)). Then, the relative luminescence efficiency was measured by variable temperature photoluminescence. The shape-engineered QD structure withstood two orders of magnitude higher defect density than the QWs at room temperature. This improvement is correlated with the activation energy for thermal evaporation of 390 meV, acquired through a kinetic model.